The conservative cavalry will boost Indiana Treasurer Richard Mourdock (R) with a massive television ad buy for his Senate campaign.

The Club for Growth announced today that it bought $800,000 in ad time to run a spot attacking the Democratic nominee, Rep. Joe Donnelly, as a "Washington liberal" on cable and broadcast.

The television buy comes just in time for Mourdock. Democrats have released several internal polls showing the two candidates have been in a statistical tie since the May primaries. Roll Call rates this race as